In order to create the file at build time, modules.builtin.ranges, that
contains the range of addresses for all built-in modules, there needs to
be a way to identify what code is compiled into modules.
To identify what code is compiled into modules during a kernel build,
one can look for the presence of the -DKBUILD_MODFILE and -DKBUILD_MODNAME
options in the compile command lines. A simple grep in .*.cmd files for
those options is sufficient for this.
Unfortunately, these options are only passed when compiling C source files.
Various modules also include objects built from assembler source, and these
options are not passed in that case.
Adding $(modfile_flags) to modkern_aflags (similar to modkern_cflags), and
adding $(modname_flags) to a_flags (similar to c_flags) makes it possible
to identify which objects are compiled into modules for both C and
assembler source files. While KBUILD_MODFILE is sufficient to generate
the modules ranges data, KBUILD_MODNAME is passed as well for consistency
with the C source code case.
Signed-off-by: Kris Van Hees <kris.van.hees@xxxxxxxxxx>
Reviewed-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
Changes since v8:
- Fixed typos.
- Explained KBUILD_MODNAME being added for consistency.
---
scripts/Makefile.lib | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index fe3668dc4954..170f462537a8 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -238,7 +238,7 @@ modkern_rustflags = \
modkern_aflags = $(if $(part-of-module), \
$(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \
- $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
+ $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) $(modfile_flags))
c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
-include $(srctree)/include/linux/compiler_types.h \
@@ -248,7 +248,7 @@ c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
rust_flags = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg
a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
- $(_a_flags) $(modkern_aflags)
+ $(_a_flags) $(modkern_aflags) $(modname_flags)
cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
$(_cpp_flags)
--
2.45.2
